A welding system includes a power source configured to generate power and deliver the power to a welding torch. The power is provided in accordance with an electrode negative pulse welding regime that includes a cyclic peak, followed by a stabilization phase, then a return to a background level. The stabilization phase has a generally parabolic current shape, and is performed in a current-closed loop manner until a transition point. Resulting weld performance is improved, with a globular-like transfer mode, reduced shorts and enhanced arc stability.

The invention provides a double-power-supply switching control system for a welding machine and method. The welding machine double-power-supply switching control method comprises the steps of: continuously detecting and modifying an input voltage signal by a signal modification unit; under the control of a control unit, judging, by a judgment unit, whether to perform voltage doubling, controlling to execute voltage doubling switching action, and locking an actual input voltage mode of a welding machine by a locking unit; and finally outputting matched output current by a power supply output unit.

In certain embodiments, a system includes a welding-type system including circuitry configured to receive direct current (DC) power directly from a distributed DC bus, to generate a current using the received DC power, and to isolate the welding-type system from the distributed DC bus.

An apparatus to provide welding power. The apparatus may include a direct current-alternate current (DC-AC) power converter to output a primary current and a transformer stage. The transformer stage may include at least one power transformer to receive the primary current from the (DC-AC) power converter on a primary side of the transformer stage and to output a first voltage through a first rectifier and a first set of secondary windings disposed on a secondary side of the transformer stage. The transformer stage may further include an auxiliary set of secondary windings disposed on the secondary side to output a second voltage. The apparatus may also include a pair of active unidirectional switches disposed on the secondary side to receive the second voltage from the auxiliary set of secondary windings.

A digitized variable-polarity welding power source based on SiC IGBT, comprising a main circuit and a control circuit. The main circuit comprises a three-phase rectifying filter circuit, a SiC IGBT primary inverter circuit, a high-frequency transformer, a SiC ultrahigh-frequency rectifying filter output circuit, a SiC IGBT secondary inverter circuit and a high-voltage arc stabilizing circuit which are sequentially connected. The control circuit comprises a controller and a power supply control module, and a digitizing tablet, a SiC primary inverter driving module and a SiC secondary inverter driving module which are in connection with the controller via signals.

Disclosed example power systems include an enclosure, an engine within the enclosure; and a generator within the enclosure and configured to convert mechanical power from the engine to electrical power. The enclosure includes a first air inlet on a first end of the enclosure, a first air outlet on a top of the enclosure, and a second air inlet on a side of the enclosure to provide a second airflow through the enclosure. The power system further includes an engine fan configured to generate a first airflow from the first air inlet to the first air outlet to cool the engine. The power system includes a diverter located below the first air outlet and configured to direct environmental contaminants away from at least one of the engine or the generator, where the environmental contaminants enter the enclosure through the first air outlet.

An example welding power supply includes: power conversion circuitry configured to convert supply power to welding current and to output the welding current to at least one of a shielded metal arc welding (SMAW) electrode, a gas tungsten arc welding (GTAW) electrode, or a gouging torch; a voltage sense circuit configured to measure an output voltage of the power conversion circuitry; and control circuitry configured to: determine a droop slope based on an arc control parameter; determine a reference voltage corresponding to an amperage parameter; set a target current by adjusting the amperage parameter based on the droop slope and based on a difference between the output voltage and the reference voltage; and control the power conversion circuitry using a current-controlled control loop based on the target current.

Systems and methods are disclosed relating to welding-type power supplies. In some examples, the power supplies may have no vents, which may help prevent environmental contaminants from entering the power supplies. Instead, the power supplies include one or more thermal interfaces configured to conduct heat generated by internal circuitry of the power supply from the interior of the power supply to an exterior of the power supply. Additionally, the thermal interface(s) may be configured for attachment to one or more exterior heat dissipating devices.

A non-consumable electrode arc-welding method is provided for causing a welding machine to output or stop a welding current in accordance with at least an ON state and an OFF state of a start signal. In the method, a start signal is switched between an ON state and an OFF state, thereby controlling the on/off operation of the welding machine. Further, an operation mode instruction signal is switched between a normal mode and an interval mode, thereby controlling the operation mode of the welding machine. When the operation mode instruction signal indicates the interval mode and also the start signal is in the ON state, the welding current is outputted in a welding current output period. Then, the output of the welding current is suspended in a welding current interval period successively following the welding current output period.

In certain embodiments, a system includes a welding-type system including circuitry configured to receive direct current (DC) power directly from a distributed DC bus, to generate a current using the received DC power, and to isolate the welding-type system from the distributed DC bus.